Osteogenic potentials of osteophytes in the cervical spine compared with patient matched bone marrow stromal cells

BACKGROUND: Osteophytes that form adjacent to degenerated disc have osteogeic potential. Studies suggest that their formation is associated with mesenchymal precursors arising from the chondrosynovial junction. This study is aimed to determine the cellular aging and osteogenic differentiation potential of osteophyte-derived mesenchymal cells (oMSCs) when compared to patient-matched bone marrow stromal cells (bMSCs). MATERIALS AND METHODS: oMSCs and bMSCs were isolated from tissue samples during anterior cervical discectomy and fusion surgery. Extensive expansion of cell cultures was performed and early and late passage cells (P(4) and P(9), respectively) were used to study cell senescence and telomerase activity. Furthermore, osteogenic differentiation was applied to detect their osteogenic capacity. RESULTS: The proliferation capacity of oMSCs in culture was superior to that of bMSCs and these cells readily underwent osteogenic differentiation. Our results showed that oMSCs had higher telomerase activity in late passages compared with bMSCs, although there was no significant difference in the telomerase activity in the early passages in either cell types. The telomerase activity was detectable only in early passage oMSCs and not in bMSCs. CONCLUSIONS: Our results indicate that oMSCs retain a level of telomerase activity in vitro, which may account for the relatively greater longevity of these cells, compared to bMSCs. Furthermore, when compared to bMSCs, oMSCs maintained a higher proliferative capacity and the same osteogenic capacity, which may offer new insights of tissue formation.